1. Field of the Invention
The present invention relates to a unit for packaging and applying a liquid product. The invention is most particularly suited to the packaging and application of cosmetic products such as nail varnishes, lipsticks, oils, gel-type oils, etc. Applications in fields other than cosmetics may also be envisaged, particularly in the field of glues, writing correctors, household stain removers, etc. Liquid products with a viscosity between that of water and that of an oil, even a gel-type oil, are particularly suitable for use according to the present invention.
2. Description of the Related Art
Stain-remover-pad-type devices exist which consist of a product reservoir surmounted by a neck at the top of which is an applicator in the form of a thin foam pad which is applied to a surface to be treated, for example the skin or a fabric. As the applicator pad is confined in the top part of the neck, loading the pad with product requires it to be turned upside down and its surface pressed several times on the surface to be treated in order to prime and load it with product. The pressure exerted on the applicator causes the opening of a valve which, in the closed position, separates the applicator from the product. Such applicators generally contain formulations which include polymers which dry up rapidly when they are not used because they are too far from the solvent medium surrounding the product contained in the reservoir and physically separated from the liquid by valve or pump-type means.
In the case of other products of the polish type, the applicator pad is separated from the product by means of a valve which further accelerates the drying-up of the applicator, sometimes rendering it unusable after a long period during which it has not been used, or requiring cleaning operations prior to any further use.
Furthermore, applicators are known which are in the form of a block of foam which is soaked in the product to be applied and then, after wiping, either on the neck of the flask or by means of a mechanical wiping device, is applied to the surface to be treated. The applicator is generally secured to the top. In certain circumstances, however, it is difficult to use, for example in the case of public transport, owing to the independent nature of the applicator and of the reservoir which, under certain use conditions, means that the container has to be held in one hand and the product applied with the other.
Patent application EP-A-0 721 748 describes an applicator for a viscous cosmetic product which has a body forming a reservoir for the cosmetic product and an applicator member which can be moved between a closed position in which the applicator member is completely engaged inside the body and an open position, in which the applicator member projects outside the body of the applicator, which can be closed by a top when the applicator member is located inside. Closing-off means are provided in order, in the closed position of the device, to prevent any liquid communication between the reservoir and the applicator. Such closing-off means enables the solvent evaporating above the surface of the product to come into contact with the applicator so as to limit the risks of drying-out, but rules out the possibility of having the applicator ready for use when the top is removed.
Patent application EP-A-435 758 describes an applicator for a perfume or other product, which includes a flask delimiting a base and, at the end opposite the base, a permeable top for applying the product, particularly to the skin. The permeable top is supplied with product by capillary effect via, in particular, a wick or a capillary tube. One of the problems associated with such a design is linked to the supply of the applicator end-piece. This supply, essentially by capillary effect, requires a certain period of time to elapse between two applications. Moreover, a method of supply of this type does not allow the application surface to be supplied with products containing pigments of the type which may be encountered in the cosmetics industry, particularly mascaras, nail varnishes or the like.
Therefore, one of the objects of the invention is to provide a packaging and application unit which is automatic, clean, and easy to use in all circumstances.
A further object of the invention is to provide a packaging and application unit in which the applicator does not dry out substantially and is therefore always ready for use, even after a long period during which it is not used.
Yet another object of the invention is to provide a reliable system which is economical to produce.
According to the invention, these and other objects are achieved by producing a unit for packaging and applying a liquid product, comprising a reservoir containing the product and having an opening; removable means for closing off the opening in a leaktight manner; an applicator fitted inside the reservoir, the applicator including a first end in permanent liquid communication with the product inside the reservoir and a second end opposite the said first end. The second end forms an application surface which is movable axially between a first position in which the application surface emerges outside the reservoir through the opening in order to apply the product and a second position in which the application surface is contained inside the reservoir. The applicator comprises at least one block of an absorbent material which is capable of being compressed at least partially, particularly when the product is applied or when the applicator is in the second position. In the second position, the application surface is preferably contained in the neck.
Thus, when the compressed block of foam relaxes, either after an application, upon opening of the cap which may keep it compressed, or at the time of any other decompression phase, it pumps product via the open or semi-open cells which form it so that the applicator is always laden with product and thus always ready for a further application. In other words, the applicator is loaded with product essentially by compression/decompression of the compressible and absorbent part of the applicator. By using an applicator which has open or semi-open cells appropriate to the size of any pigments contained in the product, products can be pumped which could not be pumped with conventional applicators of the xe2x80x9cfeltxe2x80x9d or wick type.
The expression xe2x80x9cpermanent liquid communicationxe2x80x9d reflects the fact that, at all times, both in the application position (first position) and in the storage position (second position), at least the first end of the applicator is in contact or capable of coming into contact with the liquid contained in the reservoir. In other words, it is not physically separated from the product by a valve, a pump or by any other closing-off means. This is reflected in the fact that either the first end soaks in the product or it is connected by means of a wick-type member soaking in the product or it is quite simply contained physically within the same volume (above the free surface of the product) so that, at the time of a movement such as may arise from transporting the unit, the first end cannot fail to be placed in contact with the product. As the applicator includes at least one foam-type block with open or semi-open cells, which is capable of pumping the liquid, it will always be loaded, or even saturated, with product and will thus always be ready for use. The actual pumping of the product is principally mechanical (compression/relaxation of the foam). Moreover, in the case of certain formulations, owing to their rheology, solvent may rise in the direction of the surface of the applicator by means of capillary effect or effect of surface tension with the cells of the block of foam or other alveolar or porous material. This makes it possible to further minimize drying-out of the applicator over a long period during which it is not used.
Advantageously, the reservoir consists of a body, a first end of which is closed by a base and a second end which is surmounted by a neck, the opening being delimited by a free edge of the neck, the applicator being at least partially inside the neck. The inner surface of the neck may have at least one groove, in the form of a helix, for example, so as to improve the air-uptake passage, this air uptake being permitted also by the presence of the open or semi-open cells which form all or part of the applicator. The neck may have an axis which is different from the body axis. Alternatively, the reservoir consists of a tube closed by a weld line. The applicator may be fitted either via the opening of the tube or via the base, before closure. Pressure exerted on the flexible walls of the tube makes it possible, if appropriate, to improve loading of the applicator with product, particularly by means of compression/decompression of a part of the applicator through the walls of the tube.
The first end may be located level with the lower edge of the neck. Preferably, however, the first end emerges substantially inside the reservoir and, in particular, inside the body of the reservoir through the lower part of the neck. Generally speaking, in the non-compressed position, the height of the applicator is preferably at least equal to the height of the neck and, more preferably, at least equal to one and a half times the height of the neck. The volume of air present between the applicator and the product is thus further reduced and this, combined with a good closure seal, prevents the applicator from drying out. The applicator is in effect held in a product-saturated atmosphere and is itself saturated with product. It is thus always ready to use. In the application position, the product does not drip even if the applicator is saturated. Application is clean and may be measured as desired. Application is done by applying the applicator surface to the surface to be treated. Product is released by means of the at least partial compression of the compressible block of the applicator. By compressing the applicator to a greater or lesser extent, the product deposited on the surface is measured appropriately, the hardness of the foam being chosen so that the pressure to be exerted in order to be able to apply a given maximum quantity of product is less than the force needed to move the application surface from the first position (application position) to the second position (return position). Once the product has been distributed, it must be spread uniformly over the surface to be treated. This spreading is achieved by passing the application surface over the surface to be treated, by simple capillary contact, so as to spread the product out in the form of a film through the action of the surface-tension forces being exerted between the application surface and the surface to be treated via the liquid, this taking place without necessarily having to exert pressure on the applicator. Depending on the percentage of open or semi-open cells in the applicator, it will thus be possible to adjust the outflow of the product in accordance with the latter""s rheology.
According to a first embodiment, the reservoir has a base opposite the opening, the first end being located substantially in the vicinity of the base so as to be permanently in contact with the product. Whenever the reservoir is opened, or after each compression of the applicator for applying product to a surface to be treated, the block of foam is decompressed, thereby giving rise to a pumping of product in the direction of the application surface. Moreover, between two uses, the solvent contained in the product may, to a certain extent, be pumped into the applicator by means of capillary effect or by the effect of surface tension as far as the application surface.
According to a further embodiment, the first end is located above the level of product in the reservoir. Contact between the applicator and the product takes place quite naturally and automatically whenever the unit is moved during its transportation, for example in the user""s handbag. Impregnation of the applicator, particularly with solvent, may be promoted by securing the applicator to a wick-type member soaking in the product.
Advantageously, the reservoir has a base opposite the opening and a body connecting the base to the neck, the base being movable axially with respect to the body so as to facilitate contact between the product and the applicator and to promote loading of the applicator with product. By way of example, the body is connected to the base by means of an extendible, xe2x80x9cbellowsxe2x80x9d-type part. Pressure exerted on the base may make it possible to compress at least a part of the applicator which, by relaxing, will absorb the product.
The applicator may be secured to the neck in an intermediate zone between the first and second ends, the passage from the first position to the second taking place by axial compression of at least that portion of the applicator which is between the application surface and the intermediate zone in response to the closing-off of the opening by the removable closure means. By way of non-limiting example, the applicator is secured to the neck by gluing, welding or by any other appropriate means (fins, tabs, etc.). By way of further example, the inner surface of the neck of the device forms a bead capable of receiving a groove provided all around the applicator.
According to a further embodiment, the applicator is fitted so as to slide inside the neck, the passage from one of the first or second positions to the other takes place by means of an axial translation movement of the entire applicator. Such a sliding movement of the applicator may be produced by ballasting means which are provided on the applicator, the passage from a xe2x80x9chead-upxe2x80x9d position to a xe2x80x9chead-downxe2x80x9d position of the packaging and application unit entraining the application surface into the first position, the passage from a xe2x80x9chead-downxe2x80x9d position to a xe2x80x9chead-upxe2x80x9d position of the packaging and application unit entraining the application surface into the second position. Preferably, the ballast means consist of weights fixed outside the applicator and inside the reservoir, and thus advantageously form mixing means for homogenizing the product. In this case, the ballast is chosen so that the force needed to insert the applicator into the reservoir is greater than the applicator compression force needed to distribute the desired quantity of product. Advantageously, and in order to make it possible to be able to use the application unit in any position including head-up, means are provided to immobilize the applicator in the first position.
According to yet another embodiment, the reservoir comprises a base in the vicinity of which the first end is located, and a body connecting the base to the neck, the base being movable axially with respect to the body, the applicator being fitted so as to slide inside the neck, means being provided for selectively varying the axial distance between the base and the neck so as to cause the applicator to move from one of the first or second positions to the other, means also being provided to hold the first end of the applicator substantially in the vicinity of the base. Therefore, the base may be connected to the body by means of a portion which forms a bellows. Alternatively, the base is formed by an elastically deformable flexible membrane.
Advantageously, the means capable of selectively modifying the axial distance between the base and the body comprises an attached base which is screwed onto the body of the unit, the screwing operation giving rise to a reduction in the axial height of the reservoir and the exit of the second end from the applicator through the neck of the device.
The means capable of holding the first end of the applicator in contact with the base may include elastic return means, a first end of which bears against a zone located in the vicinity of the neck and a second end of which bears on a zone secured to the applicator. By way of example, these elastic return means are formed by a helical spring.
The applicator may be fitted inside the neck by means of an intermediate member fitted inside the neck. An intermediate member of this type may be fitted inside the neck either forcibly or by snap-fitting, screwing, gluing, welding, etc.
According to an advantageous characteristic of the invention, the applicator is fitted so as to be able to pivot angularly with respect to its axis or with respect to a plane passing through its axis. By way of illustration, the applicator is fitted by means of a pivot mechanism.
Advantageously, the applicator consists of at least one block of foam chosen from polyurethane, polyethylene, polyester, polyvinyl chloride, polyether, NBR (natural rubber), SBR (synthetic rubber) foams, etc. The nature of the foam and the size of the cells forming it are chosen in accordance with the rheology of the material to be applied, in particular its viscosity and its surface tension, and also as a function of the desired outflow of the product. Preferably, the applicator comprises at least 10% of open or semi-open cells.
According to a further embodiment, the applicator consists of a stack of blocks of foam of various types and/or densities and/or thicknesses. This makes it possible to adapt the softness to the application and the quantity of product applied and also makes it possible to adapt the applicator to products with different rheologies. Alternatively, the applicator consists of a stack comprising at least one block of foam and at least one block of a material capable of pumping the product chosen, e.g., from sintered materials of sintered type of polyvinyl chloride, ethylene-vinyl acetate, felts, etc. In this latter configuration, the block of foam is preferably located in contact with the application surface. As mentioned above, the presence of a compressible block makes it possible, in addition to pumping the product at each decompression phase, to measure the quantity of product applied to the surface to be treated.
The application surface may have a variable shape depending on the profile of the surface to be treated. By way of example, the application surface has a shape which is concave, convex, flat, bevelled or double-bevelled, etc.
According to a further advantageous characteristic of the invention, the application surface may be covered with a covering which the product is able to permeate, of textile, perforated plastic or felt type and/or may be covered with a flock coating. Alternatively, the foam may be used directly as an application surface. Good application quality will be obtained particularly by virtue of the surface resulting from cutting the cells at the application surface. Satisfactory cutting quality may be obtained by cutting the foam using a laser or water jet. The cut edges of the cells, oriented perpendicularly to the application surface, i.e., axially with respect to the applicator, will act like the bristles of a paintbrush. Cut edges of this type promote retention of the product and its smoothing over the surface to be treated.
If the application surface is covered with a flock coating, this may consist of pile fibers of different diameters and/or type and/or height, or of a mixture of such pile fibers. The combination of a foam in which the cells have a relatively large average size (typically from 200 xcexcm to 3 mm and preferably from 700 xcexcm to 2 mm and more preferably still from 0.1 mm to 1.5 mm) with a flock-coating cover over the application surface has been proved to produce remarkable results.
The application capacity and flow of the product may be increased by forming a narrow channel or one or more slots (in the form of a cross, for example) at the center of the applicator, passing axially through the applicator.
The reservoir may be made from metal, glass or a thermoplastic material chosen from polyethylenes, polypropylenes, polyvinyl chlorides, polyethylene terephthalates, etc. In the case of a thermoplastic material, it may be produced by means of injection-blow molding, extrusion-blow molding or simple injection.
Balls may be provided inside the reservoir so as to promote homogenization of the product and to facilitate impregnation of the applicator.
If the applicator is axially free inside the neck, its first end may be mounted on a spring (for example, made from plastic) bearing against the base of the reservoir. This makes it possible to subject the applicator to a lower compression force when the cap is replaced on the device. The spring is chosen so that the force necessary for its compression is greater than the compression force of the foam required by certain applications as a function of the desired quantity of product.
According to a further variant, the unit according to the invention may comprise two applicators mounted head-to-tail inside the reservoir, the reservoir comprising, in these circumstances, a body whose first end is surmounted by a first neck and whose second end is surmounted by a second neck. Each of the necks has a free edge delimiting a first and a second opening inside which the first and the second applicator, respectively, are fitted. The operation of each of the applicators is identical to that which has been described above. A configuration of this type is particularly advantageous in that it makes it possible to use applicators which have different sizes and/or application characteristics. For example, in the case of a nail varnish, use is made of a first applicator of given section for large fingernails and an applicator of relatively smaller section for small fingernails.
The product may be a cosmetic product such as a nail varnish or a lipstick, or may be a glue, an oil, a gel-type oil, a writing corrector (xe2x80x9cTypexxe2x80x9d), a stain remover, etc.